Wash box and process of operating same



Sept. 19, 1933. c. o. PRATT WASH BOX AND PROCESS OF OPERATING SAME Filed Jan. 18, 1929 2 Sheets-Sheet 1 ATTORNEY XX W Sept. 19, 1933. c. O. PRATT WASH BOX AND PROCESS OF OPERATING SAME Filed Jan. 18', 1929 2 Sheets-Sheet 2 INVENTOR 6%: Zes 0. r ii BY Z ATTORNEY a flared dip pipe 5 whichis surrounded by a Patented Sept. 19, 1933 Aren'tori ice WASH BOX AND PROCESS OF OPERATING SAME Charles 0. Pratt, Maplewood, N. J., assignor to Semet-Solvay Engineering Corporation, New York, N. Y., a corporation of New York Application January 18, 1929. Serial No. 333,293

9 Claims.

Thisinvention relates to wash boxes or water seals of the'type generally utilized with gas generators, as for example in sets for the manufacture of blue gas or carbureted water gas. Water 5 gas generating sets usually involve a generator, a carburetor, a superheater and a wash box, the latter unit of the systemserving in part to remove tar and other products carried over by the gasas "it leaves the superheater. During the operation of the set, liquid and solid products accumulate in'the wash box and from time to time must be removed. To do this it is necessary to take the wash box out of service temporarily for cleaning purposes, thus interrupting the continuous operation of the system of which it forms a unit. a It is the purpose of this invention to provide a wash box and mode of operation therefor which will permit of continuous operation of the wash box and associated units. Accordingly, means are provided'vvithin the wash box for carrying ofi the tar and similar products substantially as fast as they are separated from the gases passingthrough thewash box. For this purpose the wash-boxis provided with an inclined bottom of suificient slope to cause the tar and other'products collected thereon to flow; down to the lowest point thereof where they may be drained on into a seal pot or a separate seal pipe and disposed of 30 by any'suitable' means. Preferably there is also provided means for distributing a solvent, such as oils obtained from coal tar, over the bottom of the box to dissolve the tar and similar products and carry thern'ofi through the drain. This latter feature is preferably used in combination with the sloping bottom and-with a separate seal pipe, and when used with a separate seal pipe certain 'resultsare obtained which will hereinafter be described. In someapplications of this invention it may be desirable to circulate the solvent from the seal pipe back to the wash box. r

A clearer understanding of this invention will behad from the following detailed description taken in connection with thedrawings-in which 4 Fig.1 is a side elevation partly in section of a Wash box constructed in accordance with this invention; and 7 *Fig. 2 is a plan thereof.

In the illustrated form of this invention there is shown a wash box comprising a round tank- 'like receptacle l' 'substantially closed and having 'an inclined bottom 2. The gases coming from a superheater or other source (not shown) are fed into the box throughthe upper flanged end 4 of bafile skirt 6. The gases after passing through the box in the usual manner pass out through outlet connection 7 in the top thereof. A. suitable washing fluid such as water may be sprayed into the box through spray pipe 8 which is positioned to provide a fine stream of water across the opening in skirt ,6. The gas in passing through the opening passes through the stream of water. Water may also be admitted through funnel 9v and pipe 10 to maintain the proper level of liquor in the box. An overflowpipe 11 extends into the box from the side to a point within the dip pipe and is provided with an adjustable overflow 12 which can be positioned to control the level of the liquor maintainedin the box during operation. The outer end of the overflow pipe is connected to the seal pipe 12 within the seal pct 13 having the usual stand pipe 14 and drain 15. The construction of the box so far recited, with the exception of the inclined bottom, is standard Wash box structure, and therefore is not described in great detail 7 .In order to remove the accumulation of tar and other products, there is a drain connection 16 at the lowermost end of the inclined bottom leading into'a tar seal pipe 17 having an overfiowconnection 18 and a drain 19. The overflow pipe 18 is provided with an adjustable overflow 18 which may be positioned to maintainin the box the level of tarliquor at any desired predetermined height, as will beexplained more fully hereafter. -Directly over the uppermost end of the inclined bottom 2 there is an inlet pipe 20 I having a funnel 21 upon its upper end and having, the other end extending downwardly through the box and terminating in two open ended branches 22 (Fig. 2) over the highest end of the bottom of the box. Oils obtained from coal tar, coal tar or other solvents may be supplied through funnel 21 and pipe 20. According to one embodimentof this invention, tar liquors from the tar seal potl'? or from any other source may be circulated through pipe 23 by means of pump 24 to pipe 20 and vthus maintained in continuous circulation providing a continuous stream of tar liquors or other solvent over the inclined bottomof the box.

Theoperation of the wash box when applied. to the gas generating systems is as follows:

Gasesfrom the superheater or other source pass into the Washbox through suitable connections to the upper end 4. of the dip pipe 5, the Wash box having the liquor content thereof. maintained at the proper level by the addition of liquor through funnel 9 and pipe 10 and through spray pipe 8 located at the outlet of skirt pipe 6. Some of the tar, and other matter carried over by the incoming gases condense and drop out and settle upon the inclined bottom 2 and due to the steep inclination flow through drain pipe 16 into tar seal 17, if such a seal be used, or through drain 16 to a suitable disposal system. During the operation the level of tar liquor in the wash box will be governed by the height of the adjustable overflow 18 in overflow pipe 18 of tar seal 17. Tar oils or other solvent may be added to the wash box through funnel 21 and pipe 20. The tar liquor accumulates in the wash box to a level determined by the positionof the adjustable overflow 18'. Above the tar level the usual water or gas liquor is provided, the dip pipe 5 terminating below the upper level of the gas liquor and above the upper level of the tar liquor. Due to the relative specific gravities of the tar liquor and gas liquor the level of the tar liquor in the tar seal pipe 17 will, of course, be somewhat higher than the upper level of the tar liquor in the wash box.

The gas in passing through the wash box flows in a circuitous path and is intimately contacted with water or gas liquor from spray 8 and also passes through the gas liquor in the wash box so that tar and the like and suspended matter given up by the gas settle through the gas liquor. The heavier viscous tars from the gas dissolve in or coalesce with the tar liquors in the wash box and the non-dissolved particles, if any, drop to the inclined bottom of the wash box and gradually flow along the bottom into the tar seal pipe 17. The tar and like material removed from the gas and the tar oils added to the wash box make up the tar liquor in the box which is maintained at a predetermined level in the wash box by suitably positioning the adjustable overflow 18, the excess tar liquor continuously flowing from the wash box into the seal pipe 17, through adjustable overflow 18', and then into and through a takeoff pipe 25 connected to the overflow 18.

During the gas making cycles the pressure on the wash box is substantially higher than during the blasting period, at which time no gas is passing through the wash box. Accordingly, during the gas making cycle the pressure in the wash box forces the tar liquor to rise in the tar seal pipe 17. The pressure in the wash box being relieved during the blasting operation the tar liquor flows back from the tar seal pipe 17 into the wash box. Due to this change in pressures a flowof tar liquor from washbox to tar seal pipe and back is set up. This flow exerts a scrubbing action on the walls of the connection between the wash box and the tar seal pipe and prevents the accumulation of tars and solid material at this point which otherwise might tend to obstruct the flow of tar liquor from the wash box to the tar seal pipe. Thescrubbing action caused by the transfer of the tar liquor from the wash box to the tar seal pipe 17, helps to dissolve the soft pitches on the bottom of the wash box in the vicinity of connection 16.

If desired an additional solvent for the tar carried over by the gases, other than the tar liquor, may be added to the wash box from time to time. Tar, tar oils or any other suitable solvent may be fedinto the wash box through funnel 21 and distributing pipes 22, the latter being arranged to distribute the flow of the solvent evenly over the highest end of the inclined bottom 2 from which it runs down over the entire bottom. According to a modification of my invention, tar

liquor or other solvent may be re-circulated from the tar seal or any other vessel serving as a gathering point for tar liquor or other solvents back through the feed pipe 20. The circulation of tar liquor through the wash box prevents the accumulation of tar and/or suspended matter in the wash box and tends to insure continuous satisfactory operation of the wash box. The washed gases pass from the wash box through the usual outlet 7 and the wash water passes out through the overflow 11 and into the seal pot 13 in the usual manner.

' It is obvious that minor changes may be made in the details of structure and method of operation without departing from the spirit and scope of the invention as defined in the appended claims.

I claim:

1. A wash box for gas generators comprising a receptacle adapted to contain washing liquid and tar liquor, said receptacle having a gas inlet and a gas outlet, means including a seal for maintaining in said receptacle a level of washing liquid above the gas inlet and below the gas outlet and means including a seal for maintaining a predetermined level of tar liquor in said wash box.

2. A wash box for gas generators comprising a. receptacle adapted to contain washing liquid and tar liquor, saidreceptacle having a gas inlet and gas outlet, means for maintaining insaid receptacle a level of washing liquid above the gas inlet and below the gas outlet, a tar liquor takeofi pipe at the bottom of said receptacle and a tar seal pipe connected to said takeoff pipe.

3. A wash box for gas generators comprising a receptacle adapted to contain washing liquid and tar liquor, said receptacle having an inclined bottom, a gas inlet and a gas outlet, means for maintaining in said receptacle a level of washing liquid above the gas inlet and below the gas outlet, a tar liquor takeoff pipe at the lowermost portion of the inclined bottom and a seal pipe connected to said takeoff pipe.

4. A wash box for gas generators comprising a receptacle adapted to contain washing liquid and tar liquor, said receptacle having an inclined bottom, a gas inlet and a gas outlet, means for maintaining in said receptacle a level of washing liquid above the gas inlet and below the gas outlet, a tarliquor takeoff pipe at the lowermost portion of the inclined bottom, a seal pipe connected to said takeoif pipe and an adjustable overflow device operatively connected to said seal pipe and arranged to be positioned to determine the level of the tar liquor in said wash box.

5. A wash box for gas generators comprising a receptacle having a gas inlet and a gas outlet, means for maintaining in said receptacle a level of washing liquid above the gas inlet and below the gas outlet, an inclined bottom for the receptacle, an outlet in the receptacle at the lowermost part of the inclined bottom, a takeoff pipe connected to said outlet, a seal associated with said takeoff pipe, and an inlet arranged to deliver liquor to the uppermost part of the inclined bottom.

6. A wash box for gas generators comprising a receptacle having a gas inlet and a gas outlet, means for maintaining in said receptacle a level of washing liquid above the gas inlet and below thegas outlet, an inclined bottom for the receptacle, an outlet in the receptacle at the lowermost part of the inclined bottom, an inlet arranged to deliver a solvent upon the uppermost part of the inclined bottom, and means for maintaining a predetermined level of the solvent in the receptacle.

7. A Wash box for gas generators comprising a receptacle having a gas inlet and a gas outlet, means for maintaining in said receptacle a level of washing liquid above the gas inlet and below the gas outlet, an inclined bottom for the receptacle, an outlet in the receptacle at the lowermost part of the inclined bottom, an inlet for a solvent arranged to deliver the solvent upon the uppermost part of the inclined bottom, and connections from said outlet to said solvent inlet and a pump therein for circulating said solvent-through said wash box.

8. A wash box for gas generators comprising a receptacle adapted to contain tar liquor and wash liquid, said receptacle having a gas inlet and a gas outlet, means for introducing wash liquid into the receptacle, means for withdrawing wash liquid and tar liquor from said receptacle, means for maintaining in said receptacle a level of washing liquid above the gas inlet and below the gas outlet and means for maintaining a predetermined level of tar liquor in said wash box.

9. The method of removing tar and suspended material from a wash box of a gas generating set which comprises flowing a solvent for the tar through the wash box in one direction and reversing the direction of flow to cause the solvent to flow in an opposite direction through the wash box.

CHARLES O. PRATT. 

